Polyhydric alcohol esters



Patented Sept. 28, 1948 UNITED ST'AT Es PATENT OFFICE roLrnYnmc ALCOHOLss'rsas Melvin De Gr'oote, University City,'and Arthur F. Wirtel,Kirkwood, Mo., assignors to Petrolite Corporation, Ltd., Wilmington,Del., a corporation of Delaware' No Drawing. Original application July13, 1945, SeriaLNo. 604,993. Divided and this app'iication November 5,1946, Serial No. 707,978

8' Claims. (01. 260-405) This invenion relates to new chemical productsor compounds, and to the manufacture of said Another object is toprovide a practical method of making said new materials or chemicalproducts.

The new materials, compositions of matter, or chemical products hereindescribed, consists of an ester product containing a polyhydric alcoholradical, a diglycollic acid radical, and a plurality of acyloxy radicalsll RCO as great as the total number of said polyhydric alcoholhydroxyls. In other words, the number of the groups comprising anacyloxy radical derived from a detergent-forming monocarboxy acid thatare ester-linked to each polyhydric alcohol radical, is in each instanceequal to the valency of the polyhydric alcohol radical, so that in theester product each polyhydric alcohol radical is free from anyuncombined hydroxyl radical directly attached thereto, and the number of.such' groups ester-linked to each polyhydric alcohol residue isadditional to the number of such groups ester-linked to any otherpolyhydric alcohol residue contained in the ester.

Detergent-forming monocarboxy acids are those acids having at least 8carbon atoms which have the capacity to react with alkali to form soapor soap-like products, and are exemplified by fatty acids containing 8to 32 carbon atoms, such as oleic, linoleic, ricinoleic, stearic,hydroxystearic, palmitic, linolenic, erucic, clupanodonic, myristic,etc., and fatty acids of the character referred to are normally regardedas preferable. The term detergent-forming monocarboxy acid includesnaphthenic acids. Naphthenic acids'are derived from various petroleums,or are 2 obtained by treatments which involve oxidation of hydrocarbonbodies present in the naturally- .occurring crude oils. The number ofcarbon atomsfin naturally-occurring naphthenic acids may vary from 10carbon atoms to 32 or even 38 carbon atoms. Naphthenic acid'oradmixtures of the type available on the open market and which preferablyhave a saponlflcation value in the neighborhood of about 250 aresuitable.

'Naphthenic acids of the kind referred to are readily esterified withglycerol to form naphthenin on intimate admixture and agitation in thepresence of dried hydrochloric acid gas, using a procedure that issubstantially the same as that usually in the formation of stearin fromstearic acid and glycerol. It is known that such naphthenic acids can betreated, for example, with halogens so as to produce derivatives such aschloronaphthenic acids. Also included among the detergent-forming acidsare those monocarboxy acids sometimes called wax acids or paraflinacids, which are formed as a result of oxidation of paraflin orpetroleum waxes, particularly those derived from paraflin in basehydrocarbons and which include hydroxylated, as well as non-hydroxylatedacids. Acids occurring in certain waxes, such as carnaubic acid, ceroticacid, lanopalmic acid and lanoceric acid, are considereddetergent-forming monocarboxy acids. Rosin and resinic acids, such asabietic acid are likewise included. Such acid materials, due to the factthat they react with alkalis to form soap or soap-like products, arecommonly called detergent-forming acids.

The terms hydroxylated detergent-forming acids and hydroxydetergent-forming acids, refer to those detergent-forming acids whichcontain in the acyl radical thereof an hydroxyl or the equivalent. Themost common types of hydroxylated detergent-forming carboxy acids arehydroxylated fatty acids containing 8 to 32 carbon atoms, such asricinoleic acid, monohydroxy and dihydroxystearic acid,trihydroxypalmitic acid, etc. Ester products adapted for use as rawmaterials in the invention herein described, contain at least oneradical of an hydroxylated detergentforming acid, and preferably, suchradical is a radical of an hydroxylated fatty acid containing 8 to 32carbon atoms. In addition, hydroxylated detergent-forming acids, such ashydroxylated wax acids, may be used,

While the terms detergent-forming monocarboxy acid and hydroxylateddetergent-forming monocarboxy acid include oxidized acids, as well asacids in their naturally-occurring state, those fatty bodies which aredrastically-oxidized have distinctive properties and characteristics andcertain ester products containing such drasticallyoxidized bodies areclaimed in our co-pending ap- H crmcHotgucrncn=cmcrmtooon which may beregarded as coming within the more generic formula ormooorr whereinOHRCOO is representative of the acyloxy group of any hydroxylateddetergent-forming carboxy. acid. It OHRCOO is the acyloxy group ofricinoleic acid, triricinolein may be represented by the formula:

onaooocm' ormcooon onacoo H:

and contains the residue of the polyhydric alcohol glycerol which may berepresented as onom OH H

* OH H: Triricinolein readily esterifles with diglycollic acid, and ifthree moles of diglycollic acid are caused to react with one mole oftrirlcinolein, an ester product will be obtained according to thefollowing reaction:

OH.RCOOCH:

. H H 3HOOC.gOg.COOH 0H.RCOOCH OHJRCOOCH:

nooo.ooc.coo.ncoocn H H l H n noodgogdooncoo E+smo H HHOOC.?IOICI.COO.RCOOCH1 compounds are contemplated wherein each hydroxylof each polyhydric alcohol is esteri'fled with a group containing anacyloxy radical derived from a detergent-forming monocarboxy acid having8 to 32 carbon atoms. It is not necessary that each of the hydroxylscontained in an acyloxy radical be esterifled, although this is acharacteristic of preferred'compounds contemplated herein. For example,the hydroxyl in only one or two of the ricinoleic residues may bereplaced by a glycollic acid residue.

In carrying on the esterification reaction, it is not essential that acarboxylic group of the diglycollic acid react with the alcoholiformhydroxyl in the acyloxy radical of an hydroxylated detergent-formingacid body while the acyloxy radical of the detergent-forming carboxyacid remains directly connected with the polyhydric alcohol radical.Thus, in the esterification reaction above mentioned, there may be somemolecular rearrangement with the production of a compound which may berepresented by the following formula:

E H HOOCR.OOC.COC.COOCH1 H H HOOCR.OOC.COC.COO H H HHOOCR.OOC.ICIO%.COOCH1 The compound above represented is likewisesuitable i'or use for breaking oil field emulsions. It is to be notedthat in this compound also there is the characteristic occurrence of agroup containing at least one acyloxy radical derived from I adetergent-forming carboxy acid esterified with each hydroxyl ofpolyhydric alcohol. In this particular example the group containing theacyloxy radical (RCOO) that is, esterifledlwith the hydroxyls of thepolyhydric alcohol, is the group:

H H HO0CR.OOC.COC.COO

' H n H. oooa.ooc.coc.coo H, H H

wherein the number of groups containing 'an acyloxy radical derived froma detergent-forming monocarboxy acid and esterifled with hydroxyls ofeach polyhydric alcohol (two glycol residues in the example abovegiven), is less than the total number of polyhydric alcohol hydroxyls.In the example given there is a total of four polyhydric alcoholhydroxyls and only two groups containing an acyloxy radical derived froma detergentforming monocarboxy acid esterifled therewith.

While the modifications wherein the acyloxy radical derived from thedetergent-forming carboxy acid remains directly connected to thepolyhydric alcohol residue is normally preponderant and is normallypreferred, the other modifications wherein one or more of thediglycollic acid radicals becomes directly attached to the polyhydricalcohol radical are suitable.

, In the foregoing and in subsequent formulae, a conventional showing intwo dimensional form is resorted to, and no attempt other than this ismade to indicate actual space molecular formula. Moreover, distinctionsbetween isomeric form are to be disregarded.

As a further example of the practic of this It is also possible thatduring the esterification there may be only partial molecularrearrange'-' ment, so that in the resulting product, one acyloxy radicalof a detergent-forming monocarboxy acid may be directly linked to thepolyhydric alrectly linked to a diglycollic acid radical, which. inturn, may be directly linked to th polyhydric alcohol radical. Thus, inthe foregoing reaction involving glycol, a reaction product may beformed corresponding with the formula:

H II noocn.0oc.cc.coocm I: n

n n noocgogcooawoocm and such compounds are also suitable for breakingoil field emulsions.

It is not essential that each of the acyloxy radicals derived from adetergent-forming acid that is present in the ester product for each ofthe hydroxyl groups of the parent polyhydric alcohol be hydroxylated, solong as at least one of the acyloxy radicals is hydroxylated, andthereby affords in the partial ester at least one hydroxy wherein OHRCOOis an hydroxylated acyloxy cohol radical and another acyloxy radical ofa detergent-forming monocarboxy acid may be diradical derived from anhydroxylated detergentforming acid, such as ricinoleic acid,hydroxystearic acid, or the like. and wherein RG00 is an acyloxy groupderived from a non-hydroxylated detergent-forming acid, such as oleicacid, palmitic acid, stearic acid, abietic acid, etc. Hydroxylatedesters of the mixed type, such as those exemplified above, will readilyreact with diglycollie acid to form an ester product suitable forbreaking oil field emulsions.

A wide variety of polyhydric alcohols may be employed, both of the etherand non-ether types. The following are illustrative of partial esterswhich are derived from polyhydric alcohols of the ether type and whichare suitable for reaction with diglycollic acid.

1H onncon ormcoo 1 OHRCOO Diglycerol tetraricinoleatoHo-RC00.0IH40CfBl-OOCR-OH Diothylone glycol diricinoleata Examples ofother polyhydric alcohols from which suitable ester products may bederived, are triglycerol, triethylene glycol, dipropylene glycol, alphabeta gamma butane triol, beta methyl glycol glycerol ether, 1,3 propanediol, isobutylene glycol, mono'ethylene glycol glycerol ether, mannitol,sorbitol, sorbitol monobutyl ether, erythritol, adonitol, sorbitan,mannitan, etc.

As mentioned above, it is preferable to carry on the esterificationreaction, so that at least one carboxyl group remains for each polybasiccarboxylic acid residue. However, those products are suitable that areproduced by a reaction such that each of the carboxyl groups of thepolybasic carboxy acid reacts with an alcoholiform hydroxyl. Thus, if amolecular quantity or triricinolein is heated, to approximately C. orhigher, with one molecular quantity or diglycollic acid, the reactionproduct may ultimately involve two of the hydroxyls of thetrirlcinolein, with lessor water, as indicated in the following formula;

mcoocmoocs'n:

'HCOOCILOOQHi nlcoocaon It is normally preferable, however, to controlthe esteriflcation reaction so that there is at least one free carboxylgroup present in the ultimate ester product. This an be accomplished byavoiding an'excessively high temperature or prolonged periods ofreaction. The preferred prodnot containing at least one free carboxylgroup, per molecule, is the product that is most readily prepared incommercial production.

In carrying on the esteriflcation reaction there may develop crosslinkages either through the polyhydric alcohols or through thediglycollic acid, due to the polyfunctionality of these materials. Forexample, in an esteriflcation reaction between triricinolein anddlglycollic acid, the resulting product may comprise more complexmolecules, such as the following, which illustrate cross linkage throughthe polyhydric residue.

H H HQCOOCR.OOC.ICIOg.COOH

' H H H:COOCR.OOC.COC.COOCH1 n n n 000.000.0001:

H H HICOOCRDOC-COC-COOCH:

H H H OOCR.OOC-COC.COOH

Cross linkage likewise may occur through the diglycollic acid to aifordmolecular structures, such as H H nooc.coc.coo.ncoocm no.1zcoo 11 HaC.COO.RC00 Ha C.C00.RCOOCH| H:

HO.RCOOC H H H HOOC.COC.COO.RCOO H:

H H a It is apparent that other cross linkages may occur. Such esterproducts containing more comaudios illcation there may be somepolymerization, and

polymerized products as well as simple monomers may be used.

In the ester product the presence of a residual hydrcxyl group islargely immaterial, provided the residual hydroxyl is not directlyattached to a polyhydric alcohol residue. Any such residual hydroxylgroup may be left as such, or if desired, reacted either with additionaldiglycollic acid, or with any monobasic detergent-forming carboxy acid.Alternatively, any such residual hydroxyl may be acylated withmonocarboxy acids containing less than 8 carbon atoms. The ester productcovered hcrein may include such simple acylated derivatives; but thefinished product must contain at least one acyloxy radical derived froma detergent-forming monobasic carboxy acid havingat least 8 carbon atomsin a group that is esterifled with each hydroxyl group of eachparentpolyhydric alcohol. Referring to any residual carboxyl group orgroups,- it is preferable that such group or groups be left as such.

An acidic carboxylic hydrogen atom may also be replaced by reaction withan alcoholiform hydroxyl of an hydroxylated acid. The acidic hydrogenatom may also be replaced by a residue of a monohydricalcohol, e. g.,aliphatic alcohols,"

such as methyl; ethyl, propyl. hexyl, octyhdecyl, cetyl ceryl, etc.:-alicyclic alcohols, such as cyclohexanol and the like; or aralkylalcohols, such as benzyl alcohol, naphthyl ethyl alcohol, and the lke.Similarly, the acid hydrogen may be replaced by reaction with an etheralcohol. such as those derived by reacting any of ,the foregoingalcohols with an alkylene oxide such as ethylene oxide, propyleneoxide,butylene oxideor the like (but excluding compounds such as glycide orthe like) typical ether alcohols of the kind mentioned being illustratedby the following formulae:

By reacting hydroxyaromatic compounds, such as phenol, naphthol and thelike with an alkylene oxide, such compounds can be converted tomonohydroxy aralkyl others which are suitable, and such compounds,together withaliphatic, alicyclic and aralk-yl alcohols and alcoholethers, are rereference is made to an ester product containing a freecarboxyl group, it is intended that the product contain a COOH group, inwhich the acidic hydrogen atom has not been replaced. The

' oxide,

a herein described products containing ,a carboxylic group areintendedto contemplate the-acid as such. or in the form of an' ester, asmentioned hereinabove. Since, however, products contain- While referencehas been made hereinabove to various detergent-forming monocarboxyacids, it

is apparent that simple derivatives, such as the i halogenatedcompounds, are functional equivalents. For example, chlorinatedricinoleic acid, or chlorinated triricinolein may be employed instead ofricinoleic acid or triricinolein. Bmminated olelc acid may be usedinstead of oleic acid.

Likewise, hydrogenated abietic acid maybe used instead of abietic acid.In such cases, the mono-- basic detergent-forming carboxy material,notwithstanding modifications of the kind indicated,

still has the same functional properties as the unmodified material,vand thus acts in'the same manner, as-far as esteriflcation reactions orthe' character herein described are concerned. It is also'possible, forexample, to'condense two-moles of ricinoleic acid'and-produce one. moleof monobasic diricinoleic acid. Likewise, monobasic triricinoleic acidand monobasic tetraricinoleic acid may be used. Also the'condensationproduct of a substance such as ricinoleic acid or hydroxy stearic acid,.with some low molal hydroxy-acid such as lactic acid, may be used. Itis to be un-, derstood that the term detergent-forming monobasic carboxyacid includes such functional equivalents.

Generally speaking, the majority of the esters hereinabove described aresubstantially waterinsoluble, i. e., are not soluble in 1 part to l,000partsof water at 50 Water solubility can be ethylene glycol, such asthe-following:

' onncoooni- H H moomcogp'oon noocgogcooncoooma '0 3,11HOOC.COC.CO0.RCOO H liaturally, if ethylene glycol is replaced by ,di-

ethylene glycol, water solubility is enhanced. This is also true iftriethylene glycol, tetraethylene glycol, or some higher homologue inthe series be employed. Similarly, some other polyhydric alcohol, suchas, for. example, glycerol, diglycerol, sorbitol, sorbitan,pentaerythritol, or the like, can be treated with/an allkylene oxide,such as ethylene oxide, propyleneoxide, butylene or the like, to produceether alcohols, or more specifically, etherifled diols or etherifiedtriols, in which the ether linkage occurs one time or perhaps severaltimes, at .each original hydroxyl position. Thus, following suchprocedure, one may obtain-compounds which are actually water-soluble. Ina broader sense, then, the compounds herein-contemplated may beon-s01-uble, or oil-insoluble, they may be' water-soluble, or water-insoluble,and may, in fact, show" little or no solubility in either oil or ,water.This latter statement is something of a paradox,'-but his to beemphasizedthat these esters are frequently effective at enormousdilutions, when used as demulsifiers for 'water lu-oil emulsions.-

as examples where n in the following formula represents values from 7 to15. Compare this formula with an analogue involving ricinoleic acidester of ethyleneglycol:

'11 H HOOC,gOg.C OO.RCOOCIIH1 (CaHiO), l .l

H H l HOOC.COC.COO.RCOOCH:

Nonaethyleneglycol hexaricinoleate, a product which is commerciallyavailable, is of distinct utility when converted into acidic glycollicacid esters.

In the preparation of esterification products, the esterificationreaction may be caused to take place readily upon the application ofheat, the reaction being more rapid the higher the temperature that isemployed, but care should be taken not to employ excessively hightemperatures which would cause decomposition. The reaction may, ifdesired, be in the presence of an inert solvent, such as xylene, whichmay be removed upon .the completion of, the reaction. When water isformed as a reaction product, the esterification reaction may beconducted under a reflux condenser, using a water trap to-remove wateras it is formed. The reaction can also be hastened by passing throughthe reacting materials a dried inert gas such as nitrogen or CO2. Acatalyst, such as toluene sulphonic acid, may be added to the extent ofabout one-half to 1 by weight, if desired. Generally speaking, however,the reactions take place rapidly, quickly and completely by simplyheating substances to enter into the reaction in desired stoichiometricproportions at a temperature above the boiling point of water, usuallybetween about 110 and 160 0., providing there is no decomposition. Themost desirable products are obtained by combinations in which the ratioof moles of diglycollic acid to moles of particular material reactingtherewith are within the ratios of 1 to 3 and 3 to 1.

Esterification reactions of the kind contemplated are used for theproduction 01 a wide variety ot'esters, resinous materials, sub-resinousmaterials, and include plasticizers. Attention is directed to. thefollowing patents which are a- 20, 1934; Lawson 1,909,196, May 16, 1933;Kessler 1,714,173, May 21, 1929;.Van Schaack 1,706,639,

Mar. 28, 1929; Jones 2,264,759, Dec. 2, 1941; WM-

zel 1,732,392, Oct. 12,

1929; and Groves et al. 1,993,738, Mar. 12, 1935.

Attention is directed to a comprehensive article entitled Polyhydricalcohol esters of fatty acids, their preparation, properties, and uses,by H. A. Goldsmith, in Chemical Reviews,'volume 33, December 1943,number 3.

The following are specific examples of the preparation of preferredproducts, for use for the particular purposes herein indicated:

Example 1 One pound mole of triricinolein (in the formof castor oil,which ordinarily contains approximately :to triricinolein) is reactedwith one pound mole of diglycollic acid to produce a mixture of acid.diglycollates' consisting essentially of tririclnolein monobasicdiglycollate. The reaction may be caused to occur by heating the mixedmaterials at a temperature of approximately to C. for approximately 6 to12 hours. The reaction can be followed roughly by withdrawing a smallsample of the partially reacted mass and permitting it to cool on amatch crystal. When the reaction has become completed, no crystals ofdiglycolli-c acid appears. When the same no longer shows the presence ofsuch crystals on cooling, it can be titrated with a standard volumetricalkaline solution to indicate that the acidity which remains obviouslyis due entirely to carboxylic hydrogen and not to any unreacteddiglycollic acid.

Example 2 Same procedure as followed in Example 1, except that one usestwo pound moles of diglycollic acid instead of one pound mole.

Example 3 Same procedure as followed in Example 1, preceding. exceptthat 2% to 2% pound moles of diglycollic acid are used for each poundmole of triricinolein.

Example 4 Same procedure as is employed in the preceding three examples,except that a temperature of approximately 150 to C. is employed.

Example 5 The same procedure is followed as in Examples 1 to 3,preceding, except that a temperature of 180 to 200 C. is employedExample 6 Example 7 The neutral ester derived from rlcinoleic acid andethylene glycol, that is, ethylene glycol diricinoleate, is substitutedfor triricinoleln, in preceding Examples 1 to 5, inclusive,.except thatthe ratio of diglycollic acid is changedto correspond to one and also to1 /2 pound moles of the dicarboxy acid for each mole of ethylene glycoldirlcinoleate.

Example 8 The same procedure is followed as in Example 7, preceding,except that glycols which enhance the hydrophile property are employed,as. for exnonaethylene glycol diricinoleate.

It-is to be noted that similar compounds are readily derivable from theuse of either hydroxystearic acid, for. example, or a polyricinoleicacid,

such as diricinoleic acid or triricinoleic acid, in-

stead of' the ordinary monoricinoleic. V 'I'he esteriflcation products,according .to Exricinoleic acid which is .amples 1 to 8, are viscous,yellowish materials resembling somewhat blown castor oil in consistency.For the most part, they are only slightly soluble, in either water or inparailln base mineral oil (not more than 1 part to 1,000), but go intosolution with lower alcolmls (methyl to octyl) to form a clear solution.The solutions may be made up in equal parts, for example. Example 8'typifles the type in which oil solubility, if anything, decreases butwater-solubulity increases. Oil-solubility can be, of course, increasedin an obvious manner. The simplest procedure is to eliminate part of thehydroxylated fatty acids,

such as ricinoleic acid and substitute non-hydroxylated fatty acids,such as oleic acid. or if desired, an acid such as naphthenic acid. Forexample, one can obtain a mixed glyceride from one mole of ricinoleicacid and two moles 'of naphthenic acid, or from two moles of ricinoleicacid and one mole of naphthenic acid. Similarly, naphthenic acid (oroleic. acid) combinations can be obtained from pentaerythritol, in whichone to three moles of ricinoleic acid appear and the reremaininghydroxyls are esterifled with either naphthenic acid or oleic acid.

As specific examples of chemical compounds typifying-the products hereinobtained, one may point out that the following appear as constituents ofone or more of the previous examples, .to

wit, triricinolein monodiglycollate, triricinolein di-triglycollate, ortriricinolein triglycollate.

In the preparation of esters. particularly complete asters fromdetergent-forming monocarboxy acids. and particularly higher fattyacids, one may employ other procedures. See Oil and Soap, volume 21, No.5, page 145, and volume 22, No. 3, page 57. For instance,pentaerythritol tetraricinoleate can be prepared-by treatingpentaerythritol with keto'ne so as to prepare the tetraaoetate, andlikewise, treating triricinolein with methyl or ethyl alcohol, so as toform methyl or ethyl ricinoleate, and reacting such low molaltetra-acetate under conditions described in the aforementioned articles,so as to yield methyl or ethyl acetate and pentaerythritoltetraricinoleate. We wish to emphasize the fact that the mostoutstanding compounds herein contemplated for breaking of petroleumemulsions, particularly from the viewpoint of effectiveness asdemulsiflers, as well as case and economy of manufacture, are thoseobtained by reaction between one pound. mole of triricinolein, and. aplurality of poundmoles of diglycollic acid, without any subsequentchange in respect to the unoombined carboxylic hydrogen atoms. Noteparticularly, Examples 2 to 5, inclusive, preceding. "Such compounds areso outstanding that they represent, in effect, an invention within aninvention. Such compounds of outstanding eiiectiveness for breakingpetroleum emulsions are limited to those which are 12 employed for avariety tant purposes include (1) use as demulsiilers for breakingpetroleum emulsions, as previously mentioned; and (2) use as a breakinducer in sweet- Sutton.

ening hydrocarbon oils in the manner described in U. 8. Patent No.2,157,223, dated May '7, 1939, to

Some Of the ester products above described are somewhat soluble in oil,while others are substantially insoluble in oil. If the ester product issuch that only one part or less is soluble (as determined by usualvisual methods) in- 1,000 parts of ordinary straight-run kerosene fromPennsylvania cru'de, the product is to be regarded as substantiallyinsoluble in oil. Most of the ester products hereinabove described aresub-resinous in character and of a viscous or balsam-like consistency.In the case of some of the interacting materials, especially thepolyhydroxylated fatty bodies, it is possible by prolonged heating atrelatively high temperatures to obtain a product that is of a hard,horny character, and lacks appreciable solubility in oil or in loweraliphatic alcohols. Care should be taken not to produce such hard andtotally oil-insoluble or alcohol-insoluble bodies.

As to using compounds of the kind herein described as flooding agentsfor recovering oil from substantially insoluble in both crude oil and inwater.

subterranean strata, reference is made to the procedure described indetail in U. 8. Patent No. 2,226,119, dated December 24, 1940, to DeGroote and Keiser. As to using compounds of the kind herein described asdemulsiilers, or in particular as surface tension depressants, incombination with mineral acid or acidization of oilbearing strata,reference is made to U. S. Patent No. 2,233,383, dated February 25,1941, to De Groote and Keiser.

The polyhydric alcohol esters herei'n contemplated for reaction withdiglycollic acid, may be considered as being in the class of analcohol, 1. e., a monohydric alcohol or a 'polyhydric alcohol. Forinstance, a mixed glyceride ester containing two oleyl radicals and onericinoleyl radical, would exemplify a monohydric alcohol, whereas. amixed ester having one oleyl radical and two ricinoleyl radicals, or,for that matter, triricinolein, would represent a .polyhydric alcohol.If an alcohol is indicated by the formula:

Y'(OH)1.

where n indicates the number 1 or more, and ii diglycollic acid beindicated for convenience by the formula:

xwcoomi then the reaction between a polyhydric alcohol and diglycollicacid will readily result in a compound which may be indicated by thefollowing formula:

cases, that the alcohol actually would be a polyhydric alcohol, thenexamination reveals that the formula might result in a combination, inwhich there were neither residual carboxyl radicals, nor residualhydroxyl radicals, or might result in compounds in which there wereresidual hydroxyl radicals and no residual c'arboxyl radicals, orcompounds where there might be residual carboxyl radicals and noresidual hydroxyl radicals,

of purposes. Two impor- 13 or there might .be both. This is indicated bythe following:

in which q indicates a small whole number (one in the case of a monomer,and probably not over 10 and usually less than 6, and m and n indicatethe number 1 or more, and m" and n" indicate a small or moderately-sizedwhole number, such as 0, 1 or more, but in any event, probably a numbernot in excess of 10. Actually, the preferable type of reagent would bemore apt to contain less than 10, and in fact, less than free hydroxylradicals. It is not necessary to remark that residual carboxyl radicalscan be permitted to remain as such, or can be converted in any suitablemanner, into an ester. Conversion into the ester would be by means of amonohydric alcohol, such as methyl alcohol, ethyl alcohol, propylalcohol, butyl alcohol, hexyl alcohol, etc.

For practical purposes, however, we have found that the most desirableproducts are obtained by combinations, in which the ratio of thealcoholic reactant to the acid is within the ratio of three to one andone to five, and in which the molecular weight of the resultant productdoes not exceed 8,000, and is usually less than 5,000, and preferably,less than 3,000. This is particularly true if the resultant product issoluble to a fairly deflnite extent, for instance, at least 5%, in somesolvent, such as water, alcohol, benzene, dichloroethyl ether. acetone,cresylic acid, or the like. This is simply another way of stating thatit is preferable that the product be of the type which is commonlyreferred to as an A resin or a B resin, as distinguished from a C resin,which is a highly infusible, insoluble resin (see Ellis, Chemistry ofSynthetic Resins (1935), pages 862, et seq.)

In recapitulating what has been said previously, the product hereincontemplated, may be indicated by the following formula:

I (00011)..." (Q I =')q in which the characters have their previous s18-niflcance, and y represents a small whol number not greater than 3, and:2 represents a small whole number not greater than 5; q is a smallwhole number less than 10, and preferably 1 to 5, Z represents ahydrogen ion equivalent, such as a hydrogen atom, or an organic radicalderived from a monohydric alcohol.

Materials having the repetitious unit appear 3 to times and having aplurality of free car- 'boxyl radicals or free hydroxylradicals, orboth,

are well known in a variety of forms and find practical application indemulsification of crude oil emulsions. Generally speaking, themolecular weight of such sub-resinous materials, regardless of class. isless than 10,000 and is more apt to be in a range of 3 to 5,000 as anupper limit. Amore elaborate description of this type of materialappears in numerous patents concerned with demulsification of crude oilemulsions, and reference is made to such patentsfor a more elaboratedescription.

Attention is directed to our co-pending applications Serial Nos.604,994, now Patent No..

2,442,074 issued May 25, 1948, 604,995, new abandoned, 604,996, nowabandoned, 604,997, now Patent No. 2,442,075, issued May 25, 1948,604,998, now abandoned, 604,999, now Patent No. 2,442,076 issued May 25,1948, 605,000, now abandoned, 605,001, now abandoned, and 605,002, nowPatent No. 2,442,077, issued May 25, 1948, filed July 13, 1945, all ofwhich are related to the present application, in that such co-pendingapplications are concerned, among other. things, with the breaking ofoil field emulsions by means of demulsiflers containing a diglycollicacid radical,

Having thus described our invention, what we claim as new and desire tosecure by Letters Patent is:

1. An acidic partial ester containing: (a) at least one polyhydricalcohol radical; (b) at least one diglycollic acid radical; and (0) aplurality of acyloxy radicals, each having 8 to 32 carbon atoms derivedfrom any detergent-forming monocarboxy acid having 8 to 32 carbonsatoms, with instance to the valency of the proviso that at least one ofsaid acyloxy radi-' cals is the acyloxy radical of anhydroxylateddetergent-forming monocarboxy acid having 8 to.32 carbon atoms, each ofsaid polyhydric alcohol radicals being ester-linked with a pluralit ofgroups, each of said groups contains at least one of saidacyloxyradicals, the number of said groups ester-linked to each polyhydricalcohol radical being at least equal in number in each the polyhydricalcohol radical, so that each polyhydric alcohol radical is completelyesterified and being additional to the number of such groupsester-linked to any other polyhydric alcohol radical contained in theester, and at least one of said groups containing a free diglycollicacid radical.

2. An ester, as described in claim 1, wherein there is present onepolyhydric alcohol radical.

3. An ester, as described in claim 1, wherein there is present only onepolyhydric alcohol radical and each of said acyloxy radicals is anacyloxy radical derived from a fatty acid havin 8 to 32 carbon atoms.

4. An ester, as described in claim 1. wherein there is present only onepolyhydric alcohol radical; each of said acyloxy radicals is an acyloxyradical derived from a fatty. acid having 8 to 32 carbon atoms, and eachof said acyloxy radicals is an acyloxy radical derived from anhydroxylated fatty acidhaving 8 to 32 carbon atoms.

REFERENCES crrnn The following references are of record in the file ofthis patent:

UNl' TED STATES PATENTS Name Date Guillaudeu Apr. 16, 1940 Number

